Drill bits use rotary energy provided by a drill string to cut through downhole formations, thus advancing the drill string further into the ground. To use drilling time effectively, sensors have been placed in the drill string, usually in a bottom-hole assembly found in the lower end of the drill string, to assist the operator in making drilling decisions. In the patent prior art, equipment and methods of conveying and interpreting sensory data obtained from downhole have been disclosed.
For example, U.S. Pat. No. 6,150,822 to Hong, et al., which is herein incorporated by reference for all that it contains, discloses a microwave frequency range sensor (antenna or wave guide) disposed in the face of a diamond or PDC drill bit configured to minimize invasion of drilling fluid into the formation ahead of the bit. The sensor is connected to an instrument disposed in a sub interposed in the drill stem for generating and measuring the alteration of microwave energy.
U.S. Pat. No. 6,814,162 to Moran, et al., which is herein incorporated by reference for all that it contains, discloses a drill bit, comprising a bit body, a sensor disposed in the bit body, a single journal removably mounted to the bit body, and a roller cone rotatably mounted to the single journal. The drill bit may also comprise a short-hop telemetry transmission device adapted to transmit data from the sensor to a measurement-while-drilling device located above the drill bit on the drill string.
U.S. Pat. No. 5,415,030 to Jogi, et al., which is herein incorporated by reference for all that it contains, discloses a method for evaluating formations and bit conditions. The invention processes signals indicative of downhole weight on bit (WOB), downhole torque (TOR), rate of penetration (ROP), and bit rotations (RPM), while taking into account bit geometry to provide a plurality of well logs and to optimize the drilling process.
U.S. Pat. No. 5,363,926 to Mizuno, which is herein incorporated by reference for all that it contains, discloses a device for detecting inclination of a boring head of a boring tool.
The prior art also discloses devices adapted to steer the direction of penetration of a drill string. U.S. Pat. Nos. 6,913,095 to Krueger, 6,092,610 to Kosmala, et al., 6,581,699 to Chen, et al., 2,498,192 to Wright, 6,749,031 to Klemm, 7,013,994 to Eddison, which are all herein incorporated by reference for all that they contain, discloses directional drilling systems.